The present invention relates to the field of portable computer systems. In particular the present invention discloses a portable computer system that can easily be expanded to handle many new add-on peripherals.
Handheld computer systems have become a very popular form of computing device. Handheld computer systems allow users to access large amounts of personal information such as an address book, a personal calendar, and a list of to-dos. In particular, the Palm(copyright) series of palm-sized computer systems from Palm Computing, Inc of Santa Clara, Calif. (a division of 3Com Corporation) have become the de facto standard of handheld computer systems.
However, users have been demanding additional functionality from handheld computer systems. For example, Casio has introduced a Windows CE based palm-sized personal computer that performs voice recording. Although different models of mobile computer systems can be introduced that add additional features, it is desirable to include a hardware interface on a handheld computer system. The hardware interface n a handheld computer system that new peripheral devices to be added to the existing handheld computer system.
The Palm(copyright) series of palm-sized computer systems includes an external serial interface for communicating with external peripherals. However, an external serial interface is limited due to the limited communication bandwidth and limited interface features. It would therefore be desirable to provide another system for allowing peripheral devices to couple to a mobile computer system. Ideally, the external interface should allow many different types of peripheral devices to be used.
An expandable handheld computer system is disclosed. The handheld computer system includes a peripheral expansion interface that allows a large number of different sized expansion peripherals to be created. The peripheral expansion interface is formed with a pair of rails that form a first opening wherein a peripheral device may be inserted. Expansion peripherals may extend in a first dimension out of said opening. The rails also form a second opening along a second direction orthogonal to said first dimension. Expansion peripherals may also extend outward in the second dimension.